Blood Test, Sigmoidoscopy Often Miss Colorectal Cancers

PORTLAND, Ore-A new study from The New England Journal of Medicine reports that fecal occult-blood testing and sigmoidoscopy often fail to find one-quarter of advanced neoplasia cases.

David A. Lieberman, MD, from the Veterans Affairs Medical Center in Portland, Oregon and David G. Weiss, MD, from the Veterans Affairs Medical Center in Perry Point, Maryland, tested 2885 asymptomatic patients during their study. The mean age of the group was 63 years. Most of the patients were male; each had a stool sample tested, a sigmoidoscopy procedure, and a colonoscopy procedure.

Researchers found that 45.7% of the group had no polypoid lesions, while 16.4% had hyperplastic polyps or nonadenomatous polyps. They also reported 27.3% had one or more tubular adenomas.

Of those with advanced neoplasia (306 subjects), 23.9% had a positive fecal occult blood test. Sigmoidoscopy procedures identified the neoplasia in 70.3% of this same subgroup.

Together, the two methods identified 75.8% of subjects with advanced neoplasia, leaving one-fourth of patients with the condition undiagnosed.

The researchers concluded from their findings that a colonoscopy for the screening of peole without symptoms is necessary. The reported that even though cost and patient preference issues are prevalent, a colonoscopy is the most efficient method of screening for colorectal cancers.

They recommend a single colonoscopy at age 50 and again 10-15 years later if no precursory lesions are found.

Information from, Reuters Health